Mechanisms Underlaying Regulation of Synaptic Transmission in Hippocampus by Hydrogen Peroxide

Abstract

Latest findings provided evidences of the important role of reactive oxygen species in cellular signal processes. In this study we examined the action of hydrogen peroxide on synaptic transmission in the hippocampus. Millimolar concentrations of hydrogen peroxide decreased fEPSP amplitude evoked in the CA1 region of rat hippocampal slices. GABAA receptors antagonist picrotoxin, ryanodine receptors antagonist dantrolene, ATP-sensitive potassium channels antagonist tolbutamide had no influence on the inhibitory effect of hydrogen peroxide whereas non-specific adenosine receptors antagonist caffeine blocked fEPSP depression by hydrogen peroxide, indicating that synaptic transmission inhibition involved adenosine receptors activation. Pretreatment of slices with hydrogen peroxide before the addition of adenosine had no effect on the fEPSP depression caused by adenosine suggesting that functional properties of adenosine receptors are not affected by hydrogen peroxide.